Radio engineer: Consumer Reports iPhone 4 testing flawed

An engineer experienced with electromagnetic issues like those now affecting Apple's iPhone 4 says that the tests performed by Consumer Reports were scientifically flawed.

In response to the iPhone 4 technical findings reported by the consumer buying advice group, engineer Bob Egan observed on his own site that "Consumer Reports' [radio frequency] engineers should know better than to think they can run an engineering grade test for an issue like this in a shielded room. And certainly not one with people in it."

Egan explains, "To even reasonably run a scientific test, the iPhone should have been sitting on a non-metallic pedestal inside an anechoic chamber. The base station simulator should have been also sitting outside the chamber and had a calibrated antenna plumbed to it from inside the chamber.

"I have not seen Consumer Reports' claim directly that the finger effect reduces the iPhones sensitivity by 20db as reported elsewhere, but unless Consumer Reports connected to a functional point inside the iPhone that number is fantasy.

"Even the way they seem to have tested the change ? by varying the base station simulator levels ? seems to assume the iPhone receiver and/or transmitter operate in a linear fashion (the same way) across all signal strengths ? bad assumption.

"Bottom line: from what I can see in the reports, Consumer Reports replicated the same uncontrolled, unscientific experiments that many of the blogging sites have done."

While there is little controversy surrounding the fact that some changes can be observed in iPhone 4 signal bars by holding the device a certain way, and that the signal strength may impact call quality and data transmissions speeds, Egan notes that it is not known "what part of this problem is Apple?s and what part is related to the AT&T network. And we don?t know how the observed effect is, or is not, similar to other devices.

"We also don?t know if placing a finger on the antenna bridge is detuning the antenna or detuning the receiver itself. And neither does Consumer Reports."

Reuters and other new agencies have jumped on the latest blog posting by Consumer Reports to suggest that the groups's refusal to "recommend" iPhone 4 with a special endorsement is actually a recommendation against buying the phone.

The report by Reuters described Consumer Reports' evaluation of iPhone 4 "critical" and a "poor review," despite the fact that iPhone 4 is the highest ranked smartphone in the group's mobile phone rankings. Consumer Reports does not appear to have "recommended" any smartphone model in its tests.

Update: Egan added in an email response, "Curiously the Consumer Reports 'engineers' seemed to have completely overlooked a potential very large new problem observation: you cannot measure the 'receiver' antenna problem by monitoring the output power of the phone as they did.

"Bridging the antenna gap so as to make cell phone receiver deaf (or more deaf) would normally cause the output power of the cell phone to go up to compensate, not down. Eg. the cell phone thinks its further away from the tower.

"If what we see in the video is true ? the received single strength went down- it would suggest two things; 1) touching the gap is actually making the cell phone more sensitive ? not less, or 2) the problem is not a calibration of the signal strength software calibration as admitted by Apple. Instead suggesting there is a malfunction in the cell phone power control system, or some other screwy situation.

"Of course if Consumer Reports did even a reasonable job of controlling the conditions of the test there would be some authoritative data. As I said, their work is not authoritative, and is on par with many 'blogger' tests, including my own 'trash can' tests cited elsewhere."

Egan: "[Apple] surely have a s/w issue", but on what scientific basis? Without access to the software, this is pure fantasy.

Egan: "I have not seen CR’s claim directly that the finger effect reduces the iPhones sensitivity by 20db as reported elsewhere, but unless CR connected to a functional point inside the iPhone that number is fantasy"

Stop the fantacizing. Demand Apple bring back Field Test Mode in the next iOS 4 update.

There's been a lot of bad information put out. Attenuation has been called interference. Transmit power levels called receive levels.

From the video, it looks like what was tested was the iPhone transmit power as received by their simulator. As far as I can tell, no one has measured receive power levels which are what are displayed on the iPhone bars.

This was definitely not a rigorous test but more like a demo. It would be good to have a real engineering company with experience with cell phones to take measurements, but that likely would cost more than the media is willing to pay.

Why do people even think CR is the end all be all? People just want to be told what to do by some authority. And "journalism". Most if it is desperate sensationalism to grab eye balls. Most are the info equivalent of a car salesman. It's mostly now tabloid. I'm not referring to AI right now. I'm referring to the media in general that loves to regurgitate and misrepresent facts because they have to spew something. I use my phone all the time and ignore the stupid bars but because of the lazy media I have total strangers grinning asking how the phone is with all it's problems. I just say no problems and they look confused.

My observation: I noticed the signal strength degradation/death grip thing on my own almost immediately on starting to play with my new iPhone 4 on release day. Taking even a modest amount of care in holding it the problem can be avoided altogether. Any case that covers the metal strip, which is to say any case at all, fixes it. I'm using the Bumper.

Should this have happened? No. Is it a big deal? No. Is the whole thing getting blown way out of proportion? You be the judge...

You're right... except for all those articles that don't help Apple's image. Two so far today and three yesterday, with moat articles seeming to be mostly Apple-neutral, like the MS, BMW, and AT&T articles from today.

Quote:

Originally Posted by Bregalad

So how does this scientist suggest testing the effect of a person holding a phone if the person is required to stay outside the anechoic chamber?

It's a control group. I've been saying the same thing since this issue appeared, we still don't know what the cause is. Touching the "3G-Spot" shows a result, but not the actual cause.

I thought the biggest problem for the iPhone 4 is that they're selling faster than Apple can make them.

No, that's the good part. The bad part is if this does become widely well known it says more about Apple's reputation then the issue itself. Their refusal to deal with the real issue is what the big deal will be about, if that happens. Brand image is Apple's most precious thing, and it's going to take a hit. Apple has the opportunity to swallow its pride and fix the issue. If they do they'll get respect back. If they don't then the Apple rots a little.